I am creating an outdoor summer room with recycled material but I'm having an issue with my door. It doesn't shut properly on its own, so at the moment my solution is that I have a stopper lock on the inside which I reach in through the window to lock and unlock in order to shut the door from the outside.

The door itself is too thin to put a standard lock in, like one you would use in a bathroom, because like I said it's recycled and so my door isn't actually a typical old door, it's from a shed.

Does anyone have any ideas on what I can do? I basically need a way of wedging the door shut from the outside, but in a way that if you are inside you can just push it open, without having to reach through the window etc.

Any ideas would be useful guys. Let me know if you have any more questions/comments!